<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>随机点名</title>
  <style>
    * {
      margin: 0;
      padding: 0;
    }

    .box {
      width: 600px;
      margin: 50px auto;
      display: flex;
      font-size: 25px;
      line-height: 40px;
    }

  .qx {
    width: 450px;
    height: 40px;
    color: red;
  }

  .btns {
    text-align: center;
  }

  .btns button {
    width: 120px;
    height: 35px;
    margin: 0 50px;
  }

  </style>
</head>
<body>
  <h2>随机点名</h2>
  <div class="box">
    <span>名字是：</span>
    <div class="qs">这里显示姓名</div>
  </div>
  <div class="btns">
    <button class="start">开始</button>
    <button class="end">结束</button>
  </div>
  <script>
    // 数据数组
    const arr = ['马超','黄忠','赵云','刘备','张飞','','','',]
    const qs = document.querySelector('.qs')
    // 获取开始按钮对象
    const start = document.querySelector('.start')
    // 添加点击事件 
    start.addEventListener('click',function(){
      //随机数
      const random = parseInt(Math.random() * arr.length)
      // console.log(arr[random])
      qs.innerHTML = arr [random]
    })
  </script>
</body>
</html>